1,1-Carbonyldiimidazole (CDI)

1,1'-Carbonyldiimidazole (CDI) is an organic compound with the molecular formula (C3H3N2)2CO. It is a white crystalline solid. It is often used for the coupling of amino acids for peptide synthesis and as a reagent in organic synthesis. One common extension of this scheme lies in the transacylation reaction of acids that is promoted by CDI. Although the reactivity of CDI is less than acid chlorides, it is more easily handled and its reactions have a wider scope in synthesis. CDI can also be used for esterification, although alcoholysis requires heat or the presence of a potent nucleophiles as sodium ethoxide, and other strong bases like NaH. This reaction has generally good yield and wide scope. A similar reaction involving thiols and selenols can yield the corresponding esters. The alcohol reaction can be used to form glycosidic bonds, as well.